<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #wrap{
            width: 100px;
            height: 100px;
            border: 1px;
        }
        .box{
            width: 50px;
            height: 50px;
            background-color: blue;
            border: 1px solid red;
            margin: 10px;
            padding: 10px;
            text-align: center;
            line-height: 50px;
            transition: background-color 0.5s ease-in-out;
        }
    </style>
</head>
<body>
   <div class="wrap">
    <div class="box">
        <h2>hello</h2>
    </div>
   </div>
</body>
</html>